// Created by Anderson Mancini 2023
// React Three Fiber Ultimate LensFlare
// Modified for weather app integration

import { Uniform, Color, Vector3 } from 'three'
import { BlendFunction, Effect } from 'postprocessing'
import { wrapEffect } from './util.js'
import { useRef, useMemo, useEffect } from 'react'
import { useFrame, useThree } from '@react-three/fiber'
import { useTexture } from '@react-three/drei'
import { easing } from 'maath'

const LensFlareShader = {
  fragmentShader: /* glsl */ `

  uniform float iTime;
  uniform vec2 lensPosition;
  uniform vec2 iResolution;
  uniform vec3 colorGain;
  uniform float starPoints;
  uniform float glareSize;
  uniform float flareSize;
  uniform float flareSpeed;
  uniform float flareShape;
  uniform float haloScale;
  uniform float opacity;
  uniform bool animated;
  uniform bool anamorphic;
  uniform bool enabled;
  uniform bool secondaryGhosts;
  uniform bool starBurst;
  uniform float ghostScale;
  uniform bool aditionalStreaks;
  uniform sampler2D lensDirtTexture;
  vec2 vxtC;

  float rndf(float n){return fract(sin(n) * 43758.5453123);}float niz(float p){float fl = floor(p);float fc = fract(p);return mix(rndf(fl),rndf(fl + 1.0), fc);}
  vec3 hsv2rgb(vec3 c){vec4 k = vec4(1.0, 2.0 / 3.0, 1.0 / 3.0, 3.0);vec3 p = abs(fract(c.xxx + k.xyz) * 6.0 - k.www);return c.z * mix(k.xxx, clamp(p - k.xxx, 0.0, 1.0), c.y);}
  float satU(float x){return clamp(x, 0.,1.);}vec2 rtU(vec2 naz, float rtn){return vec2(cos(rtn) * naz.x + sin(rtn) * naz.y,cos(rtn) * naz.y - sin(rtn) * naz.x);}
  vec3 drwF(vec2 p, float intensity, float rnd, float speed, int id){float flhos = (1. / 32.) * float(id) * 0.1;float lingrad = distance(vec2(0.), p);float expg = 1. / exp(lingrad * (fract(rnd) * 0.66 + 0.33));vec3 qzTg = hsv2rgb(vec3( fract( (expg * 8.) + speed * flareSpeed + flhos), pow(1.-abs(expg*2.-1.), 0.45), 20.0 * expg * intensity));float internalStarPoints;if(anamorphic){internalStarPoints = 1.0;} else{internalStarPoints = starPoints;}float ams = length(p * flareShape * sin(internalStarPoints * atan(p.x, p.y)));float kJhg = pow(1.-satU(ams), ( anamorphic ? 100. : 12.));kJhg += satU(expg-0.9) * 3.;kJhg = pow(kJhg * expg, 8. + (1.-intensity) * 5.);if(flareSpeed > 0.0){return vec3(kJhg) * qzTg;} else{return vec3(kJhg) * flareSize * 15.;}}
  float ams2(vec3 a, vec3 b) { return abs(a.x - b.x) + abs(a.y - b.y) + abs(a.z - b.z);}vec3 satU(vec3 x){return clamp(x, vec3(0.0), vec3(1.0));}
  float glR(vec2 naz, vec2 pos, float zsi){vec2 mni;if(animated){mni = rtU(naz-pos, iTime * 0.1);} else{mni = naz-pos;}float ang = atan(mni.y, mni.x) * (anamorphic ? 1.0 : starPoints);float ams2 = length(mni);ams2 = pow(ams2, .9);float f0 = 1.0/(length(naz-pos)*(1.0/zsi*16.0)+.2);return f0+f0*(sin((ang))*.2 +.3);}
  float sdHex(vec2 p){p = abs(p);vec2 q = vec2(p.x*2.0*0.5773503, p.y + p.x*0.5773503);return dot(step(q.xy,q.yx), 1.0-q.yx);}float fpow(float x, float k){return x > k ? pow((x-k)/(1.0-k),2.0) : 0.0;}
  vec3 rHx(vec2 naz, vec2 p, float s, vec3 col){naz -= p;if (abs(naz.x) < 0.2*s && abs(naz.y) < 0.2*s){return mix(vec3(0),mix(vec3(0),col,0.1 + fpow(length(naz/s),0.1)*10.0),smoothstep(0.0,0.1,sdHex(naz*20.0/s)));}return vec3(0);}
  vec3 mLs(vec2 naz, vec2 pos){vec2 mni = naz-pos;vec2 zxMp = naz*(length(naz));float ang = atan(mni.x,mni.y);float f0 = .3/(length(naz-pos)*16.0+1.0);f0 = f0*(sin(niz(sin(ang*3.9-(animated ? iTime : 0.0) * 0.3) * starPoints))*.2 );float f1 = max(0.01-pow(length(naz+1.2*pos),1.9),.0)*7.0;float f2 = max(.9/(10.0+32.0*pow(length(zxMp+0.99*pos),2.0)),.0)*0.35;float f22 = max(.9/(11.0+32.0*pow(length(zxMp+0.85*pos),2.0)),.0)*0.23;float f23 = max(.9/(12.0+32.0*pow(length(zxMp+0.95*pos),2.0)),.0)*0.6;vec2 ztX = mix(naz,zxMp, 0.1);float f4 = max(0.01-pow(length(ztX+0.4*pos),2.9),.0)*4.02;float f42 = max(0.0-pow(length(ztX+0.45*pos),2.9),.0)*4.1;float f43 = max(0.01-pow(length(ztX+0.5*pos),2.9),.0)*4.6;ztX = mix(naz,zxMp,-.4);float f5 = max(0.01-pow(length(ztX+0.1*pos),5.5),.0)*2.0;float f52 = max(0.01-pow(length(ztX+0.2*pos),5.5),.0)*2.0;float f53 = max(0.01-pow(length(ztX+0.1*pos),5.5),.0)*2.0;ztX = mix(naz,zxMp, 2.1);float f6 = max(0.01-pow(length(ztX-0.3*pos),1.61),.0)*3.159;float f62 = max(0.01-pow(length(ztX-0.325*pos),1.614),.0)*3.14;float f63 = max(0.01-pow(length(ztX-0.389*pos),1.623),.0)*3.12;vec3 c = vec3(glR(naz,pos, glareSize));vec2 prot;if(animated){prot = rtU(naz - pos, (iTime * 0.1));} else if(anamorphic){prot = rtU(naz - pos, 1.570796);} else {prot = naz - pos;}c += drwF(prot, (anamorphic ? flareSize * 10. : flareSize), 0.1, iTime, 1);c.r+=f1+f2+f4+f5+f6; c.g+=f1+f22+f42+f52+f62; c.b+=f1+f23+f43+f53+f63;c = c*1.3 * vec3(length(zxMp)+.09);c+=vec3(f0);return c;}
  vec3 cc(vec3 clr, float fct,float fct2){float w = clr.x+clr.y+clr.z;return mix(clr,vec3(w)*fct,w*fct2);}float rnd(vec2 p){float f = fract(sin(dot(p, vec2(12.1234, 72.8392) )*45123.2));return f;}float rnd(float w){float f = fract(sin(w)*1000.);return f;}
  float rShp(vec2 p, int N){float f;float a=atan(p.x,p.y)+.2;float b=6.28319/float(N);f=smoothstep(.5,.51, cos(floor(.5+a/b)*b-a)*length(p.xy)* 2.0  -ghostScale);return f;}
  vec3 drC(vec2 p, float zsi, float dCy, vec3 clr, vec3 clr2, float ams2, vec2 esom){float l = length(p + esom*(ams2*2.))+zsi/2.;float l2 = length(p + esom*(ams2*4.))+zsi/3.;float c = max(0.01-pow(length(p + esom*ams2), zsi*ghostScale), 0.0)*10.;float c1 = max(0.001-pow(l-0.3, 1./40.)+sin(l*20.), 0.0)*3.;float c2 =  max(0.09/pow(length(p-esom*ams2/.5)*1., .95), 0.0)/20.;float s = max(0.02-pow(rShp(p*5. + esom*ams2*5. + dCy, 6) , 1.), 0.0)*1.5;clr = cos(vec3(0.44, .24, .2)*16. + ams2/8.)*0.5+.5;vec3 f = c*clr;f += c1*clr;f += c2*clr;f +=  s*clr;return f;}
  vec4 geLC(float x){return vec4(vec3(mix(mix(mix(mix(mix(mix(mix(mix(mix(mix(mix(mix(mix(mix(mix(vec3(0., 0., 0.),vec3(0., 0., 0.), smoothstep(0.0, 0.063, x)),vec3(0., 0., 0.), smoothstep(0.063, 0.125, x)),vec3(0.0, 0., 0.), smoothstep(0.125, 0.188, x)),vec3(0.188, 0.131, 0.116), smoothstep(0.188, 0.227, x)),vec3(0.31, 0.204, 0.537), smoothstep(0.227, 0.251, x)),vec3(0.192, 0.106, 0.286), smoothstep(0.251, 0.314, x)),vec3(0.102, 0.008, 0.341), smoothstep(0.314, 0.392, x)),vec3(0.086, 0.0, 0.141), smoothstep(0.392, 0.502, x)),vec3(1.0, 0.31, 0.0), smoothstep(0.502, 0.604, x)),vec3(.1, 0.1, 0.1), smoothstep(0.604, 0.643, x)),vec3(1.0, 0.929, 0.0), smoothstep(0.643, 0.761, x)),vec3(1.0, 0.086, 0.424), smoothstep(0.761, 0.847, x)),vec3(1.0, 0.49, 0.0), smoothstep(0.847, 0.89, x)),vec3(0.945, 0.275, 0.475), smoothstep(0.89, 0.941, x)),vec3(0.251, 0.275, 0.796), smoothstep(0.941, 1.0, x))),1.0);}
  float diTN(vec2 p){vec2 f = fract(p);f = (f * f) * (3.0 - (2.0 * f));float n = dot(floor(p), vec2(1.0, 157.0));vec4 a = fract(sin(vec4(n + 0.0, n + 1.0, n + 157.0, n + 158.0)) * 43758.5453123);return mix(mix(a.x, a.y, f.x), mix(a.z, a.w, f.x), f.y);} 
  float fbm(vec2 p){const mat2 m = mat2(0.80, -0.60, 0.60, 0.80);float f = 0.0;f += 0.5000*diTN(p); p = m*p*2.02;f += 0.2500*diTN(p); p = m*p*2.03;f += 0.1250*diTN(p); p = m*p*2.01;f += 0.0625*diTN(p);return f/0.9375;} 
  vec4 geLS(vec2 p){vec2 pp = (p - vec2(0.5)) * 2.0;float a = atan(pp.y, pp.x);vec4 cp = vec4(sin(a * 1.0), length(pp), sin(a * 13.0), sin(a * 53.0));float d = sin(clamp(pow(length(vec2(0.5) - p) * 0.5 + haloScale /2., 5.0), 0.0, 1.0) * 3.14159);vec3 c = vec3(d) * vec3(fbm(cp.xy * 16.0) * fbm(cp.zw * 9.0) * max(max(max(max(0.5, sin(a * 1.0)), sin(a * 3.0) * 0.8), sin(a * 7.0) * 0.8), sin(a * 9.0) * 10.6));c *= vec3(mix(2.0, (sin(length(pp.xy) * 256.0) * 0.5) + 0.5, sin((clamp((length(pp.xy) - 0.875) / 0.1, 0.0, 1.0) + 0.0) * 2.0 * 3.14159) * 1.5) + 0.5) * 0.3275;return vec4(vec3(c * 1.0), d);}
  vec4 geLD(vec2 p){p.xy += vec2(fbm(p.yx * 3.0), fbm(p.yx * 2.0)) * 0.0825;vec3 o = vec3(mix(0.125, 0.25, max(max(smoothstep(0.1, 0.0, length(p - vec2(0.25))),smoothstep(0.4, 0.0, length(p - vec2(0.75)))),smoothstep(0.8, 0.0, length(p - vec2(0.875, 0.125))))));o += vec3(max(fbm(p * 1.0) - 0.5, 0.0)) * 0.5;o += vec3(max(fbm(p * 2.0) - 0.5, 0.0)) * 0.5;o += vec3(max(fbm(p * 4.0) - 0.5, 0.0)) * 0.25;o += vec3(max(fbm(p * 8.0) - 0.75, 0.0)) * 1.0;o += vec3(max(fbm(p * 16.0) - 0.75, 0.0)) * 0.75;o += vec3(max(fbm(p * 64.0) - 0.75, 0.0)) * 0.5;return vec4(clamp(o, vec3(0.15), vec3(1.0)), 1.0);}
  vec4 txL(sampler2D tex, vec2 xtC){if(((xtC.x < 0.) || (xtC.y < 0.)) || ((xtC.x > 1.) || (xtC.y > 1.))){return vec4(0.0);}else{return texture(tex, xtC); }}
  vec4 txD(sampler2D tex, vec2 xtC, vec2 dir, vec3 ditn) {return vec4(txL(tex, (xtC + (dir * ditn.r))).r,txL(tex, (xtC + (dir * ditn.g))).g,txL(tex, (xtC + (dir * ditn.b))).b,1.0);}
  vec4 strB(){vec2 aspXtc = vec2(1.0) - (((vxtC - vec2(0.5)) * vec2(1.0)) + vec2(0.5)); vec2 xtC = vec2(1.0) - vxtC; vec2 ghvc = (vec2(0.5) - xtC) * 0.3 - lensPosition; vec2 ghNm = normalize(ghvc * vec2(1.0)) * vec2(1.0);vec2 haloVec = normalize(ghvc) * 0.6;vec2 hlNm = ghNm * 0.6;vec2 texelSize = vec2(1.0) / vec2(iResolution.xy);vec3 ditn = vec3(-(texelSize.x * 1.5), 0.2, texelSize.x * 1.5);vec4 c = vec4(0.0);for (int i = 0; i < 8; i++) {vec2 offset = xtC + (ghvc * float(i));c += txD(lensDirtTexture, offset, ghNm, ditn) * pow(max(0.0, 1.0 - (length(vec2(0.5) - offset) / length(vec2(0.5)))), 10.0);}vec2 uyTrz = xtC + hlNm; return (c * geLC((length(vec2(0.5) - aspXtc) / length(vec2(haloScale))))) +(txD(lensDirtTexture, uyTrz, ghNm, ditn) * pow(max(0.0, 1.0 - (length(vec2(0.5) - uyTrz) / length(vec2(0.5)))), 10.0));} 
  void mainImage(vec4 v,vec2 r,out vec4 i){vec2 g=r-.5;g.y*=iResolution.y/iResolution.x;vec2 l=lensPosition*.5;l.y*=iResolution.y/iResolution.x;vec3 f=mLs(g,l)*20.*colorGain/256.;if(aditionalStreaks){vec3 o=vec3(.9,.2,.1),p=vec3(.3,.1,.9);for(float n=0.;n<10.;n++)f+=drC(g,pow(rnd(n*2e3)*2.8,.1)+1.41,0.,o+n,p+n,rnd(n*20.)*3.+.2-.5,lensPosition);}if(secondaryGhosts){vec3 n=vec3(0);n+=rHx(g,-lensPosition*.25,ghostScale*1.4,vec3(.25,.35,0));n+=rHx(g,lensPosition*.25,ghostScale*.5,vec3(1,.5,.5));n+=rHx(g,lensPosition*.1,ghostScale*1.6,vec3(1));n+=rHx(g,lensPosition*1.8,ghostScale*2.,vec3(0,.5,.75));n+=rHx(g,lensPosition*1.25,ghostScale*.8,vec3(1,1,.5));n+=rHx(g,-lensPosition*1.25,ghostScale*5.,vec3(.5,.5,.25));n+=fpow(1.-abs(distance(lensPosition*.8,g)-.7),.985)*colorGain/2100.;f+=n;}if(starBurst){vxtC=g+.5;vec4 n=geLD(g);float o=1.-clamp(0.5,0.,.5)*2.;n+=mix(n,pow(n*2.,vec4(2))*.5,o);float s=(g.x+g.y)*(1./6.);vec2 d=mat2(cos(s),-sin(s),sin(s),cos(s))*vxtC;n+=geLS(d)*2.;f+=clamp(n.xyz*strB().xyz,.01,1.);}i=enabled?vec4(mix(f,vec3(0),opacity)+v.xyz,v.w):vec4(v);}
`,
}

export class LensFlareEffect extends Effect {
  constructor({
    blendFunction = BlendFunction.NORMAL,
    enabled = true,
    glareSize = 0.2,
    lensPosition = [0.01, 0.01],
    iResolution = [0, 0],
    starPoints = 6,
    flareSize = 0.01,
    flareSpeed = 0.01,
    flareShape = 0.01,
    animated = true,
    anamorphic = false,
    colorGain = new Color(70, 70, 70),
    lensDirtTexture = null,
    haloScale = 0.5,
    secondaryGhosts = true,
    aditionalStreaks = true,
    ghostScale = 0.0,
    opacity = 1.0,
    starBurst = true
  } = {}) {
    super('LensFlareEffect', LensFlareShader.fragmentShader, {
      blendFunction,
      uniforms: new Map([
        ['enabled', new Uniform(enabled)],
        ['glareSize', new Uniform(glareSize)],
        ['lensPosition', new Uniform(lensPosition)],
        ['iTime', new Uniform(0)],
        ['iResolution', new Uniform(iResolution)],
        ['starPoints', new Uniform(starPoints)],
        ['flareSize', new Uniform(flareSize)],
        ['flareSpeed', new Uniform(flareSpeed)],
        ['flareShape', new Uniform(flareShape)],
        ['animated', new Uniform(animated)],
        ['anamorphic', new Uniform(anamorphic)],
        ['colorGain', new Uniform(colorGain)],
        ['lensDirtTexture', new Uniform(lensDirtTexture)],
        ['haloScale', new Uniform(haloScale)],
        ['secondaryGhosts', new Uniform(secondaryGhosts)],
        ['aditionalStreaks', new Uniform(aditionalStreaks)],
        ['ghostScale', new Uniform(ghostScale)],
        ['starBurst', new Uniform(starBurst)],
        ['opacity', new Uniform(opacity)]
      ])
    })
  }

  update(renderer, inputBuffer, deltaTime) {
    this.uniforms.get('iTime').value += deltaTime
  }
}

const LensFlare = wrapEffect(LensFlareEffect)

function UltimateLensFlare({
  position = [0, 3, 0],  // Sun position
  blendFunction = BlendFunction.SCREEN,
  glareSize = 0.35,
  followMouse = false,
  starPoints = 2.0,
  flareSize = 0.5,
  flareSpeed = 0.3,
  flareShape = 0.02,
  animated = true,
  anamorphic = false,
  colorGain = new Color(255, 165, 0),
  dirtTextureFile = 'https://i.ibb.co/c3x4dBy/lens-Dirt-Texture.jpg',
  haloScale = 0.5,
  secondaryGhosts = true,
  aditionalStreaks = true,
  ghostScale = 0.3,
  starBurst = true,
  enabled = true,
  opacity = 1.0
}) {
  const lensRef = useRef()

  const screenPosition = new Vector3(...position)
  let flarePosition = new Vector3()

  const { viewport, raycaster } = useThree()
  const lensDirtTexture = useTexture(dirtTextureFile)

  let projectedPosition

  useFrame(({ scene, camera, delta }) => {
    if (lensRef.current) {
      projectedPosition = screenPosition.clone()
      projectedPosition.project(camera)

      flarePosition.set(projectedPosition.x, projectedPosition.y, projectedPosition.z)

      raycaster.setFromCamera(projectedPosition, camera)
      const intersects = raycaster.intersectObjects(scene.children, true)

      if (intersects.length > 0) {
        const firstIntersect = intersects[0]
        
        if (firstIntersect.object.userData && firstIntersect.object.userData.lensflare === 'no-occlusion') {
          easing.damp(lensRef.current.uniforms.get('opacity'), 'value', 1.0, 0.07, delta)
        } else {
          const material = firstIntersect.object.material
          
          if (material) {
            if (material.transparent && material.opacity < 0.8) {
              easing.damp(lensRef.current.uniforms.get('opacity'), 'value', material.opacity * 0.5, 0.07, delta)
            } else if (material.transmission && material.transmission > 0.2) {
              easing.damp(lensRef.current.uniforms.get('opacity'), 'value', 0.3, 0.07, delta)
            } else {
              easing.damp(lensRef.current.uniforms.get('opacity'), 'value', 0.0, 0.07, delta)
            }
          } else {
            easing.damp(lensRef.current.uniforms.get('opacity'), 'value', 0.0, 0.07, delta)
          }
        }
      } else {
        easing.damp(lensRef.current.uniforms.get('opacity'), 'value', 1.0, 0.07, delta)
      }

      lensRef.current.uniforms.get('lensPosition').value.x = flarePosition.x
      lensRef.current.uniforms.get('lensPosition').value.y = flarePosition.y
    }
  })

  useEffect(() => {
    if (lensRef.current) {
      lensRef.current.uniforms.get('iResolution').value.x = viewport.width
      lensRef.current.uniforms.get('iResolution').value.y = viewport.height
    }
  }, [viewport])

  return useMemo(
    () => (
      <LensFlare
        ref={lensRef}
        iResolution={[viewport.width, viewport.height]}
        blendFunction={blendFunction}
        lensDirtTexture={lensDirtTexture}
        glareSize={glareSize}
        starPoints={starPoints}
        flareSize={flareSize}
        flareSpeed={flareSpeed}
        flareShape={flareShape}
        animated={animated}
        anamorphic={anamorphic}
        colorGain={colorGain}
        haloScale={haloScale}
        secondaryGhosts={secondaryGhosts}
        aditionalStreaks={aditionalStreaks}
        ghostScale={ghostScale}
        starBurst={starBurst}
        enabled={enabled}
        opacity={opacity}
      />
    ),
    [
      glareSize,
      blendFunction,
      starPoints,
      flareSize,
      flareSpeed,
      flareShape,
      animated,
      anamorphic,
      colorGain,
      haloScale,
      secondaryGhosts,
      aditionalStreaks,
      ghostScale,
      starBurst,
      enabled,
      opacity,
      viewport.width,
      viewport.height
    ]
  )
}

export default UltimateLensFlare